Chainsaw Repair

How To Basics - Carb Fixes + Mods - IPL and Service Manuals => How To Basics and Fixes => Topic started by: 660magnum on August 24, 2013, 09:30:09 pm


Title: E15 ANOTHER FUEL FIGHT
Post by: 660magnum on August 24, 2013, 09:30:09 pm
 Another fuel fight... This was written by a guy (a Mr Horning) in the SW USA that works on small engines. Where he lives, (sometimes in Northern Mexico) he has a lot of trouble with the fuel going bad . . .

    There are some that claim that ethanol in the fuel does no harm in our small two stroke engines, and those that claim that it certainly does. Personally, I think for people that use their equipment regularly, like once a week, that ethanol laced gasoline probably does no damage. This is assuming that the fuel system has up to date components of course. But I think for engines and fuel systems that sit for long periods of time, the ethanol does result in collateral if not direct damage/problems. The only other thing I can add is that I used to be a Rotax Authorized Service Center. (Rotax engines are by far the most commonly used engines in Ultralight airplanes.) Rotax was stern in their warnings that gasoline with ethanol was NOT to be used in their two stroke engines.

    Here is an interesting paragraph posted by Popular Mechanics relating to the problem:

    Will this damage my lawnmower, boat, jet ski, snowmobile, or four-wheeler?

    It sure will if you don't pay attention. Generally, small two stroke engines are not designed to deal with the more corrosive E15 blend. And, as we mentioned in 2010, ethanol forms a brown goo when left in a fuel tank too long, which can clog fuel-system components. Two-stroke engines run hotter with an ethanol blend, which accelerates the potential damage. And ethanol can wreak havoc on fiberglass fuel tanks in older boats. Groups like the National Marine Manufacturers Association and Outdoor Power Equipment Institute have issued strong warnings to consumers to pay attention to their fuels or risk severe engine damage. Use a fuel stabilizer if the engine will sit for more than a few weeks without use; this will reduce the ethanol–water separation and potential gumming issues. Be careful to avoid using E15 in uncertified engines like these, at least until the subject is studied more thoroughly, and the engineering catches up to the fuel.


    http://www.popularmechanics.com/cars/alternative-fuel/biofuels/four-things-to-know-about-e15-15096134

I do have small engines that sit unused for long periods of times. I used to have a lot of problems with stiffening of fuel lines and more troublesome, stiff carb diaphragms. So now I use a "Storage Fuel" which consists of Coleman Camp fuel mixed 20 to 1 with Pennzoil for Air Cooled Engines and a dash of Sta-Bil for good measure. I remove the running fuel when done sawing, put half a tank of the "Storage Fuel" in, and run the engine long enough to be sure the fuel has gotten all through the carb and engine. I then choke the engine to kill it, and store it with the "Storage Fuel" in the tank. I do not recommend running Coleman fuel for work whatsoever.

Anyway, the "Storage Fuel" has solved virtually all my fuel system problems and I use it religiously.

Relative to the above post in the paragraph from Popular Mechanics; one clarification. Ethanol in the fuel will NOT make an engine run hotter, IF the mixture is richened to compensate for the ethanol. Ethanol needs a much richer mixture than pure gasoline. So if you add ethanol to the gas, and do not then richen the mixture, it will run hotter because the fuel mixture has effectively been leaned out due to the addition of the ethanol. Actually, with a proper fuel mixture, an engine running with a percentage of ethanol added should in fact run slightly cooler.
Title: Re: ANOTHER FUEL FIGHT
Post by: Al Smith on August 26, 2013, 09:13:33 pm
To a point some of that makes sense .For example any alcohol fuel requires 40 percent more fuel than straight gasoline to get the same power .Alky vaporizes much faster than gasoline .Going from a greater concentration to a lesser as would be the case of fuel through a carb would have the same effect  as refridgeration with freon vaporizing .It would get cooler to some degree than straight gasoline .However it would take more of same to get the same power hench a richer mixture .Plays the dickens with the carb and seals though which kinda sucks .
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Cut4fun on June 30, 2014, 09:48:05 am
copy pasted below

Look Before You Pump Gasoline for Outdoor Power Equipment

When you pull up to a gasoline filling station, you may start to see some changes. The gas you put in your car may no longer be safe for small engines, UTVs and outdoor power equipment.

To learn more: http://opei.org/ethanolwarning/

http://youtu.be/pz34vhT2_Nc
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Cut4fun on June 30, 2014, 09:52:57 am
other link copy pasted some from it.

http://opei.org/ethanolwarning/   

LOOK BEFORE YOU PUMP

When you pull up to a gasoline filling station, you may start to see some changes. The gas you put in your car may no longer be safe for small engines, UTVs and outdoor power equipment.
The equipment affected include: mowers, garden tractors, chain saws, boats, snow throwers, trimmers, UTVs, power washers, blowers, chippers, grinders, generators, jaws of life, concrete saws and other compact construction equipment, as well as small engine applications such as water pumps and irrigation systems, and other additional small engines.
To learn more, click on the appropriate section below.

PRICE is No Longer the Best Way to Select Gasoline

Most gasoline now contains 10 percent ethanol (E10). But, you may see higher ethanol blended gas available for sale – such as 15, 30, 50 or 85 percent ethanol gas – at a gasoline filling station.

These higher ethanol blends may even be cheaper than E10, and you might be tempted to buy the higher ethanol content gasoline because of its lower cost. But, price is no longer the way to choose your gasoline safely. You have to choose the right fuel for the right application.

Higher ethanol blends (above 10% ethanol) are not meant for outdoor power equipment such as mowers, garden tractors, chain saws, boats, snow throwers, trimmers, UTVs, power washers, blowers, chippers, grinders, generators, jaws of life, concrete saws and other compact construction equipment, as well as small engine applications such as water pumps and irrigation systems.

Are higher ethanol blends really that harmful to outdoor power equipment?

Yes. You might be tempted to use a higher ethanol blended fuel since it may be less expensive. However, greater than 10 percent ethanol in outdoor power equipment can corrode metals and rubber and cause engines to break down more quickly. Most outdoor power equipment was not built, designed or warranted to run on fuel greater than E10, and using higher ethanol blends can damage or destroy it. In fact, using any fuel that contains more than 10 percent ethanol is illegal to use in outdoor power equipment.

Also, the higher the ethanol blend, the lower the fuel economy. Ethanol contains 33 percent less energy per gallon than gasoline, so engines fueled with higher ethanol blended gas will attain fewer miles per gallon than those running on conventional gasoline (E10). This means you must fill your gas tank more frequently when using higher ethanol blended fuel.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: 660magnum on June 30, 2014, 11:04:24 am
I get a sneaking suspicion that the local fuel around me has varying amounts of Ethanol, even from the same pump, from week to week?

E10 might be 5% and it may be 25% locally even though it says E10 on the pump?
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: KilliansRedLeo on June 30, 2014, 11:32:51 am
I read someplace that the ethanol we get does not come blended from the refineries it is most often blended by the distributors. And there are no QA standards that I know of that the distributors must follow.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Cut4fun . on June 30, 2014, 12:52:08 pm
Tim this happen in 2012  To much Ethanol warning  http://chainsawrepair.createaforum.com/war-room/to-much-ethanol-warning/msg10409/#msg10409


Marathon and Speedway issue small-engine fuel warning for gasoline


Advisory from Marathon Petroleum, essentially stating that consumers should avoid using their gas for anything with a small engine. At least for awhile.

Apparently, the Findlay, Ohio-based petroleum refiner got too much ethanol in its gasoline formula, which might cause implement such as mowers and leaf blowers to run hotter than they’re designed to handle.

Marathon Petroleum – Small Engine Fuel Advisory

 Marathon Petroleum has identified a product quality situation at one of its terminals resulting in gasoline containing more than 10 percent ethanol in the counties surrounding the greater Louisville area, excluding Jefferson county. Adjacent counties in southern Indiana have also been impacted. Fuel with excess ethanol has the potential to cause small engines such as chainsaws, leaf blowers, generators, lawn mowers, snow blowers, etc., to run faster and hotter than normal, which may result in safety-related issues.

This fuel should not cause drivability or safety issues with respect to automobiles.

If you purchased gasoline since March 3 from Marathon Brand or Speedway locations Marathon Petroleum recommends that you do not operate small engines containing this fuel.

Marathon Petroleum is continuing to identify other retail locations in the impacted areas that may have been supplied with this gasoline and will provide additional information as soon as it becomes available. If you have a concern regarding your gasoline, please contact the retailer to determine if it was supplied by Marathon Petroleum.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: 660magnum on June 30, 2014, 02:44:18 pm
Marathon is one of the biggest fuel suppliers in this area of North Central Ohio.

No matter what station you go to around here, it is likely supplied by Marathon.

They have refineries in Findley, Ohio, Canton, Ohio, & Catletsburg (Ashland) Ky on the Ohio river.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Eccentric on July 01, 2014, 03:23:59 am
I get a sneaking suspicion that the local fuel around me has varying amounts of Ethanol, even from the same pump, from week to week?

E10 might be 5% and it may be 25% locally even though it says E10 on the pump?
I read someplace that the ethanol we get does not come blended from the refineries it is most often blended by the distributors. And there are no QA standards that I know of that the distributors must follow.

You fellows are right on.  We've been having that problem (inconsistent eth levels) in gasoline here (in Ca) since the mid 1990's when eth gas was foisted on us as a replacement for MTBE (which had been foisted on us previously).  I was working in an OPE shop at that time.  We would have rashes of roached  new equipment coming in (mostly string trimmers).  We started testing the gas from the fuel tanks for eth content.  Some of it was well over 20%.  Ethanol was getting added to the fuel at multiple points along its journey from the refineries to the pumps.   Bad deal.....
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: KilliansRedLeo on July 01, 2014, 01:41:29 pm
Well Eccentric, since it is going on in Canada also, it must be some sort of multi government conspiracy foisted on us all and led by the Obama administration. Only they could have a working public health system across the border and be so omnipotent as to ignore it.

“We have to pass the (health care) bill so you can find out what is in it”!
Princess Palosi
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Eccentric on July 01, 2014, 04:24:30 pm
That administration is simply the latest (and most blatant) representation of those folks.  They're ramming through what they can while they hold most of the cards.  That's been going on here in Ca for decades.  The rest of the US is following.  I don't know enough about the governments north of the border to form an educated opinion about them...
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: aclarke on July 01, 2014, 06:36:32 pm
Is this an issue of fuel going bad and not being usable because of the alcohol or an issue related to non alcohol resistant components being damaged. I've never noticed any issues with our  saws, weed eaters etc and we use alcohol laced fuel daily.  I would imagine that the main reason Rotax is against alcohol mixed fuels in their ultralight engines has a lot to do with water obsorbtion from the alcohol and subsequent carburetor icing issues? Or is there an issue with alcohol displacing lube? Do they have the same warning on their sled engines too or jus aircraft variants?   
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Eccentric on July 01, 2014, 07:07:19 pm
Is this an issue of fuel going bad and not being usable because of the alcohol or an issue related to non alcohol resistant components being damaged. I've never noticed any issues with our  saws, weed eaters etc and we use alcohol laced fuel daily.  I would imagine that the main reason Rotax is against alcohol mixed fuels in their ultralight engines has a lot to do with water obsorbtion from the alcohol and subsequent carburetor icing issues? Or is there an issue with alcohol displacing lube? Do they have the same warning on their sled engines too or jus aircraft variants?   

It's several issues.  These come to mind:

1)Water absorbtion. 
              A)Water in the fuel corrodes brass, steel, magnesium,  and aluminum carb components, including fuel tanks, metering lever pivot pins, metering lever springs, screws, and carb bodies. 
              B)Water corrodes bearings and rings during storage. 
              C)Water also displaces lubricant, especially if it has fallen out of suspension.
              D)When water falls out of suspension, it clogs orifices and screen/filters.  This can cause a drastic lean out.

2)Not all 2-stroke mix oils are compatible with ethanol.  Gotta look at the fine print............if it's even on the bottle.

3)Alcohol in the fuel causes the engine to run leaner and hotter at a given mixture setting.  IF the eth content is consistent, this can be adjusted for...

4)Pump gas ethanol content is often inconsistent.  See #3 for why this is bad...

5)Ethanol degrades rubber fuel system components. 
           A)Degrades diaphragms.
           B)Can degrade rubber needle tips (or seat inserts, depending on the carb). 
           C)Degrades hoses (both rubber and vinyl).  This deterioration often happens from the inside out.  The hose can look and feel fine on the outside, while rubber 'gunk' sluffs off from the inside of the line and clogs metering orifices.  Leaking hoses can also draw in air, causing a lean condition.
            D)Degrades purge/primer bulbs.  This can allow air to be drawn into the system, leaning things out during operation.
            E)Degrades plastic fuel tanks and caps.  Caps split.  Mostly an annoyance and possibly a fire hazard.
            F)Degrades rubber check valves ('duckbills') in carbs (when present) fuel tanks/caps, and other areas.

I've seen the damage from most of these issues firsthand.  Others seem to never have an issue.  Ethanol doesn't mess up your equipment..........................until it does...
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: aclarke on July 02, 2014, 12:12:55 am
I agree with all the potential issues associated with alcohol and know this first hand running saws on alky and nitro. I don't, however, feel that this is as big an issue running two strokes on the 5-10% alcohol we see in the pump gas in Ca.

The last batch of saws, blowers, weedeaters we purchased for our crews were 2+ years ago and none  exhibit any negative signs of alcohol in the fuel. 

Regular use vs sitting May be a factor but I'm not convinced the small alky content is so horrible

Adam
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Eccentric on July 02, 2014, 01:38:58 am
I agree with all the potential issues associated with alcohol and know this first hand running saws on alky and nitro. I don't, however, feel that this is as big an issue running two strokes on the 5-10% alcohol we see in the pump gas in Ca.

The last batch of saws, blowers, weedeaters we purchased for our crews were 2+ years ago and none  exhibit any negative signs of alcohol in the fuel. 

Regular use vs sitting May be a factor but I'm not convinced the small alky content is so horrible

Adam

I'm not trying to convince you of anything.  You asked a question, and I answered it with my observations based on experience.  Like I said before.  Some folks seem to never have a problem running eth gas.  Others....

I've seen lots of damage from that crap in California over the last 20+ years.  It's not always 5-10% either.  I've seen test results of over 20% ethanol in pump gas in northern California.  I said all this earlier.  Are you  saying I made it up?  If eth gas works for you, keep running it.  Rest easy running your equipment on the stuff.

My guess is that you are able to get eth gas that's always fresh, and has a low, consistent ethanol concentration (at least for now).  I can tell you first hand that your situation (if that's what it is) is NOT a constant in this state.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: 660magnum on July 02, 2014, 09:03:02 am
I haven't had any gas trouble myself but I bought a Craig's List Stihl trimmer a few years ago. The engine wouldn't idle. Taking the carb apart, there was white crud inside the metering chamber of the carburetor. I tried to unplug the idle circuit but wasn't successful. A new $28 carburetor finally fixed it.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: KilliansRedLeo on July 02, 2014, 09:08:43 am
My opinion is that as long as you are running fuel through the engine regularly (several tanks a day) the effects of the ethanol are probably reduced. Every saw that I see with damage from ethanol is an occasional use tool. My pro cutter customers run it on a daily basis and are not having any huge problems, small things like fuel lines and such.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: aclarke on July 02, 2014, 09:39:03 am
Aaron, not doubting your findings. The internet as a whole is difficult to glean accurate info from and the quote from the Popular Mechanics article saying saws run hotter on methanol is a perfect  example of how misinformation gets spread.  When the mtbe gas was replaced with the ethanol fuel there were many issues created from mixing mtbe and alky laced fuels. The result of the mixing of these two fuels was a "brown sludge" which caused tons of issues and was blamed on the ethanol fuel. It didn't surface until much later that the issue was in fact the mtbe/mixed with the replacement fuel.

imho, inactive tools stored with any type fuel are going to experience more issues than regularly used power equipment . Alcohol laced fuel is clearly more corrosive and with its water holding qualities thats a big problem for tools that sit.   
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: aclarke on July 02, 2014, 10:22:36 am
Aaron, what types of issues are you seeing specifically and would they be
Exclusive to alky fuel? 
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Eccentric on July 02, 2014, 03:40:17 pm
Aaron, what types of issues are you seeing specifically and would they be
Exclusive to alky fuel? 

I'm not having any issues with my equipment now, as I switched to non-eth fuel a couple years ago.  When I still ran eth pump gas I saw the issues I listed a couple posts ago. I did not get those from some PM article or the internet.   I still see many of the issues I listed in the equipment owned by friends and family that run eth fuel. 

Not letting old fuel sit in machines does mitigate the water issues..............except when the water is already in the fuel from the gas station storage tanks.  As with ethanol concentration, the water contamination levels are inconsistent.

Running fresh eth gas does not mitigate the rubber/vinyl/plastic fuel system component degradation issues.  That's what I'm still seeing with equipment owned by friends who only run 'fresh' eth fuel (and who sometimes use the 'wonder' treatments like Startron). 

Unless the machine is drained immediately and completely after each use, the fuel system components are in constant contact with ethanol.  It's fresh..............but it's still ethanol.  There's a reason why the manufacturers keep changing the materials they use for fuel lines and other components.  I don't like running machines dry all the time either.  There are issues that come with that practice (but that's another discussion).

I also continued to see these same rubber/vinyl/plastic component issues with my own equipment before I finally found a good source of somewhat reasonably priced non-eth gas and switched for good.  Fuel lines were lasting months rather than years (same with 'duckbills').  Carb diapragms were lasting a year (at most) as opposed to multiple years.  O-rings swelled and/or ****.  Fuel caps and other plastic parts started cracking.  Etc...

Eth gas does make machines run leaner/hotter compared to non-eth gasoline at the same carburetor mixture settings as I stated previously.  That's not something made up by PM or others.  IF you are able to tune for the ethanol fuel, this can be compensated for.  Fixed jet carburetors don't allow us to compensate for it.  Limited adjustment carburetors may not allow enough adjustment to compensate either. 

Then there's the issue of eth concentration consistency (or lack thereof).  If you tune your machines for fuel with 5% concentration, and the next batch is 20%, you're going to have issues unless you can retune for that batch of fuel.

The damage I saw in the 1990's was not just "in fact" brown sludge from MTBE/eth mixing.  Saw some of that, but it wasn't the sole cause of the problems.  Letting fuel sit in machines wasn't the sole problem either.  Corrosion was not the sole problem either.  As I stated before, I saw many new (as in bought on Friday and burned up on Saturday) machines damaged by eth gas. 

MTBE was terrible stuff for different reasons, including groundwater contamination.  Heck, stations in my area had JUST completed the mandatory tank replacements (using fiberglass tanks) when MTBE became mandated.  Not long after that, it was discovered that the MTBE was goin' right through those tanks into the ground.  Several stations were shut down.  Not good.  MTBE was also terrible with rubber components.  Turned fuel lines to chewing gum.  Saw that with my own equipment.  I still remember a guy arriving at work as his fuel line (1980's S10 Blazer) completely failed.  Gas pouring onto the parking lot.  He's lucky it didn't catch fire and burn to the ground.  His fuel line was like taffy.  I actually sought out the stations that were using ethanol instead of MTBE as their mandated oxygenate (just to get away from the MTBE).  Those were mostly 76 stations at that time.  Learned (first hand) of the problems with running eth gas shortly after that...

I don't intend to keep going over this.  I've stated my observations and experiences enough.  Either you agree with my conclusions or you don't.  Doesn't matter to me.  You asked a question and I answered it.  I'm sorry that my answers don't agree with your conclusions.  Doesn't make my answers less 'valid' or give cause for suspicion that I got them from some magazine article or blog.   I'm not some yokel that read a bunch of 'internet' paranoia and/or got spun up by a PM article.   
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Cut4fun . on July 02, 2014, 04:33:35 pm
Adam I was wondering what you run for your everyday mix? 

I buy 93 octane suppose to be 10% ethanol.

I still use KL-200 and have a 7 month old batch that has set in open plastic fuel can at times.

Set some in quart glass jar to watch and not once have I seen any separation or drawing in moisture.  That I could see or tell.

I will use the Original till I cant get it. Works for me.

Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Cut4fun . on July 02, 2014, 06:35:26 pm
I have dumped guys gas out that I work on and it was dark blue color from their mix and you could see the water alky separation in their mix though. Dumped in a glass jar to look at.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: 660magnum on July 02, 2014, 06:47:45 pm
I've dumped out other's gas that was almost black. It had to be old before they put it in the saw for that strato model had only been out a couple years.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: aclarke on July 02, 2014, 08:58:19 pm
Kev
we use the Stihl HP mix in the orange bottle. Ran the Klotz and 727 for a year or so a while back but the guys complained about the smell!  I love the smell but then again I'm not exposed to the fumes as much as the workers are anymore.  We use around 15+ gal a week depending on if we're pruning or removing trees and fuel up at the same Chevron always. This station has a big turnover in fuel so perhaps we're lucky in that the fuel may be fresher. Adam
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: dutchsawdoctor on July 03, 2014, 01:36:39 am
I now use aspen fourstoke( blue can )and added mix oil to it, the best is to use the old sae 30 oil.

It wil not go bad and it won't get to the alu casting ;)
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: newowner? on August 13, 2014, 10:29:47 pm
i hope i am not re-repeating here whats been said but... i am from saskatchewan canada... and here we have regular fuel, upto 10%eth,  medium, and premium, neither medium or premium state whether they have eth or not, im assuming not, i bought a husky 450 and i bought the 3 cans of fuel for the warranty, i am out of the fuel and dont want to pay 12 bucks a quart for more, can i just buy premium and mix my own in one gallon batches? a gallon would last me quite a while because i only cut for firewood in my yard, any thoughts?
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: aclarke on August 13, 2014, 11:11:37 pm
Depending on climate, fuel quality and alcohol content you should be safe for a month or so.  We buy our company fuel weekly and the alcohol content doesn't cause any adverse issues.  I've stored mixed fuel at home for several months but we live in a dry climate
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: KilliansRedLeo on August 14, 2014, 03:57:24 am
I ran 93 octane 10% ethanol using Bel-Ray H1R @ 32:1, only in 1.5 gallon batches. It would store well for about 45 days but then would start to separate. We now have a reliable supplier of non ethanol 91 octane pure gas, I still use the same mix and it does not seem to separate, I still mix in 1.5 gallon batches but I go through quite a bit in the summer months so 1.5 gallons only lasts a week or so.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: newowner? on August 14, 2014, 08:53:56 am
Great thanks. If I was to use airplane fuel because of the higher octane should I richen the fuel oil mix?
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: aclarke on August 14, 2014, 09:50:57 am
Avgas will store for a very long time, costly though...
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: 660magnum on August 14, 2014, 09:52:42 am
Great thanks. If I was to use airplane fuel because of the higher octane should I richen the fuel oil mix?

Rather than give you a direct answer, I'll try to give you pointers to better chainsaw running no matter what changed.

I prefer to adjust the chainsaw close to the two cycle / four cycle change over point. This has always been the mixture point of choice.

You will find that this point moves around with the heat built up in the chainsaw. What I notice is a chainsaw mixture going leaner in a big buried cut before the bar is through the wood. So I prefer to adjust the mixture to the weather and the job.

A chainsaw adjusted correctly for whacking limbs will get too lean in a big long cut in a tree trunk.

Likewise a chainsaw set correctly for heavy duty cutting will be too "fat" when starting the saw and cutting off one small limb.

A chainsaw adjusted correctly for the job and temperature in very hot weather will be too lean in extremely cold weather.

Likewise a chainsaw adjusted correctly for very cold weather will be too rich for very hot weather.

Moral .  . .

Learn to identify the change over point of the 2 cycle - 4 cycle  running of the chainsaw and keep your mixture adjusted for the chainsaw to run at that point in the job being performed.
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: newowner? on August 14, 2014, 11:18:09 am
Thank you . Overwhelming but informative . How do I identify when its running lean ans rich ?  And how do I adjust?
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: 660magnum on August 14, 2014, 01:42:22 pm
Oh my?
Listen for the roughness-smoothness transition while leaning out from a too rich condition

https://www.youtube.com/watch?v=7jYUotkZorg
https://www.youtube.com/watch?v=29FiGmDQkaM
https://www.youtube.com/watch?v=WIdj-ZpygLw
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Eccentric on August 14, 2014, 10:29:38 pm
Great posts.  I agree completely.  When I read his Q I was thinking that I didn't have time to give a thorough answer.  You covered it.8)
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: newowner? on August 14, 2014, 10:54:36 pm
Awesome thanks guys  this  info  really helped!   Sorry  I'm  a noob with carbs  lol 🍺
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: Eccentric on August 14, 2014, 11:41:38 pm
This reminded me to cut/paste my 'old saw tuning instructions' Sig line into my profile here.  Been meaning to do so for a while...
Title: Re: E15 ANOTHER FUEL FIGHT
Post by: 660magnum on August 15, 2014, 07:58:20 am
+1 on the sig line